1. Technical Field
The present invention relates to offshore drilling and production platforms, and in particular to the application of a wear resistant coating to components of a keel joint used with such platforms.
2. Description of the Prior Art
In certain types of offshore oil or gas production wells, a riser assembly is used to connect a floating drilling and/or production platform with a stationary subsea wellhead. The riser assembly passes through an opening in the bottom of the platform. The riser is subject to bending movement where it enters the floating platform caused by wave action and the like. Such movement can result in stress on the components of the riser assembly. A keel joint is often used to absorb and reduce this stress. The keel joint typically includes a housing that surrounds a portion of the riser assembly. The housing includes mating keel joint components that flex or move relative to one another. The movement from the floating platform is translated to these mating surfaces. While the stress on the riser assembly may be reduced, typically there is a corresponding increase in stress on the mating components and other components of the keel joint.
The harsh environment can also cause wear to the keel joint components. Seawater, entrained sand, chemical contamination, mud and other damaging elements can corrode the component surfaces and result in unwanted galling, erosion and abrasion, as well as increase the likelihood of component degradation and eventual failure. These drawbacks are in addition to the stress and wear on the components caused by normal bearing loads and work requirements. Other offshore drilling and production components are also subject to similar conditions.